This evening I went for a drive in my 73 Mav 302. And the only thing I can think contributed to my problem is when we were in the drive thru at Jack in the box idling for what seemed to be an eternity! After that whenever I stepped hard on the gas it would accelerate as if it was missing a plug wire or two, I got worried so I pulled over and checked everything out, the distributor was really hot, I removed the cap and my pertronix was hotter than usual too. I drove some more and it was fine as long as I didn't get on it. I got myself to the freeway and cruised for a while letting the air flow through and shortly after I tried hard accelleration with no probs, I pulled over and checked the distrib and all was not nearly as hot, This whole time my temp guage was reading within normal operating temp. I recently built this engine and dropped it in about a month ago with beautiful performance untill my drive this evening, should I be worried? or are these kind of probs typical when you sit idling too long? Could the fact that my Flamethrower coil is still in the factory location be an issue? This is the first sign of any trouble since I installed this engine.... sorry so long mM
If that coil is on the intake manifold...get it off...that ain't helpin matters any...also check your plug wires very carefully. I had the same problem...my number 8 cylinder wire had some heat chaffe where it sat over the header...not touching but close enough to break down the insulation...some straight boot wires solved the problem.
Moving the coil is good advice, but I'm not convinced that is the problem. Pull your plugs and see what they look like. It could be as simple as a bad plug or bad wire (yes, you can still get a bad new one). I've found from experience (boy, could we talk!!) that keeping it simple first usually gets better results and a faster resolution. How new is the distributor cap?
I was wondering if, since its a fairly new motor and maybe not all the bugs are worked out yet(maybe) could it have sat there and be running to rich at idle and maybe fouled a plug? I am not very smart, so remember, its just me thinking out loud.
what kind of carburetor is it? I bet money it's an Edelbrock...they are notorious for this problem. The fuel percolates (boils) in the bowls and causes it to run weird at WOT. My truck did it (466 w/750 Ebrock) and my Mustang does it as well with a 600. For curing it, I don't know how to fix it....tried everything to no avail. Guess I'll just have to live with it, though, 32 MPG with a 302 is a good trade off in the Mustang!
32MPG??!!!!! What's your setup? Hell I'd quit driving my Focus if I could get the Maverick running like that!
Thanks for all your replies. The problem only last for about 10-15 minutes after pulling out from the drive thru it has been fine ever since, but when I was in that drive thru I have never let it idle that long and everything was really hot (distrib, carb etc) but cooled off after getting on the freeway. So it is no longer a problem but I wonder if I could do something to prevent it from happening again. If I fouled a plug wouldn't it still continue to run crappy? Yes I have an Edelbrock #1705, and my distrib cap is a new Blue Streak (I think) The higher priced thicker one. I plan to have it dynotuned at the end of the month, I can't wait!!:bananaman :bananaman :bananaman mM
sounds to me that you have alot of heat build up while idling....for the carb you could always go with the heat sink gaskets (havent tried them but have seen them in the jegs and summit catalogs), how about an electric fan? or even better yet if you dont drive it in real cold temperatures i would put about a 160 thermostat in it if you havent already, but like wes said keep it simple at first, always the best way
Yes, that's exactly right! I didn't believe it myself so I filled the tank and checked it 3 times. Came up with an average of 32, max of 33 and minimum of 31. That is driving REAL easy, and all highway miles. In town, its usually around 18-20. #1405 E-brock carb, old-style performer RPM intake, Flowtech long-tube headers. 302 .030" over w/lightweight SRP flat-tops @ 10.2:1 compression. Pistons are 480 grams, lightened pins are 80. They are the old pistons from my 393. Heads are '75 351w mildly ported around the valveguides and through the exhaust ports. Heres the kicker--they have 1.94/1.60 undercut titanium valves. I got them in trade for some work on a friend's house. He has been racing sprints for ages, and had these Ti valves left over from a turbocharged sprint car experiment. Also has lightened aluminum roller rockers, stock hyd roller lifters, standard steel pushrods (coudn't find any light ones LOL). Erson 226-228 @.050" .512" lift hyd roller cam installed +4 deg adv. Also has Ford motorsport windage tray in the bottom, and the crank & rods are stockers. Stock flywheel, stock damper, T5 trans with .68 5th gear, 3.73 gears. The tuning is the key. Carb has 89 jets primary with 7552 rods, and 98 secondary jets. Float height is 7/16". The timing is 14* initial 32*, half in at 1500, all in by 2000. Vacuum secondary is disconnected. I also phased the rotor to the pickup coil in the stock Duraspark dist. and the "dual" advance is via 2 different springs on the centrifugal advance. It runs so lean below 2000 rpm, that there is a slight "lean" misfire at part-throttle cruising. If you give it a slight bit of throttle to accelerate from, say, 40-70, when the motor hits 2200, you can feel it start to accelerate harder due to the cam's profile and timing change from centrifugal advance. Also, it makes good power, though not really a hotrod by any means (best run is a 11.07 @ 95 mph at a 1000' track---beat a LS1 powered 6-speed Trans Am by about 1/2 carlength). It is fun to drive though, and best of all it gets great mileage. I will have to admit it's been one of my best built and thought out engines I've ever built. Though it's capable of SO much more power, I'm not touching it as it runs well enough as is!
